Artem: rename static functions so that they do not use the "ubifs_" prefix - we
       only use this prefix for non-static functions.
Artem: remove few junk white-space changes in file.c
Signed-off-by: NSubodh Nijsure <snijsure@grid-net.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NBen Shelton <ben.shelton@ni.com>
Acked-by: NBrad Mouring <brad.mouring@ni.com>
Acked-by: NTerry Wilcox <terry.wilcox@ni.com>
Acked-by: NGratian Crisan <gratian.crisan@ni.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Artem: rename the __ubifs_setxattr() functions to just 'setxattr()'.
Signed-off-by: NSubodh Nijsure <snijsure@grid-net.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NBen Shelton <ben.shelton@ni.com>
Acked-by: NTerry Wilcox <terry.wilcox@ni.com>
Acked-by: NGratian Crisan <gratian.crisan@ni.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The journal update function did not work for extended attributes properly,
because extended attribute inodes carry the xattr data, and the size of this
data was not taken into account.

Artem: improved commit message, amended the patch a bit.
Signed-off-by: NSubodh Nijsure <snijsure@grid-net.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NBen Shelton <ben.shelton@ni.com>
Acked-by: NBrad Mouring <brad.mouring@ni.com>
Acked-by: NGratian Crisan <gratian.crisan@ni.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

We forgot to free the budget in 'write_begin_slow()' when 'do_readpage()'
fails. This patch fixes the issue.
Suggested-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

s/withing/within/
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I found the dump messages of UBIFS_SB_NODE is not aligned. This
patch remove the extra space from the line which is retracted.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This assertion was only correct before UBIFS had xattr support.
Now with xattr support also a directory node can carry data
and can act as host node.
Suggested-by: NArtem Bityutskiy <dedekind1@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Hu (hujianyang <hujianyang@huawei.com>) discovered an issue in the
'empty_log_bytes()' function, which calculates how many bytes are left in the
log:

"
If 'c->lhead_lnum + 1 == c->ltail_lnum' and 'c->lhead_offs == c->leb_size', 'h'
would equalent to 't' and 'empty_log_bytes()' would return 'c->log_bytes'
instead of 0.
"

At this point it is not clear what would be the consequences of this, and
whether this may lead to any problems, but this patch addresses the issue just
in case.

Cc: stable@vger.kernel.org
Tested-by: Nhujianyang <hujianyang@huawei.com>
Reported-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Hu (hujianyang@huawei.com) discovered a race condition which may lead to a
situation when UBIFS is unable to mount the file-system after an unclean
reboot. The problem is theoretical, though.

In UBIFS, we have the log, which basically a set of LEBs in a certain area. The
log has the tail and the head.

Every time user writes data to the file-system, the UBIFS journal grows, and
the log grows as well, because we append new reference nodes to the head of the
log. So the head moves forward all the time, while the log tail stays at the
same position.

At any time, the UBIFS master node points to the tail of the log. When we mount
the file-system, we scan the log, and we always start from its tail, because
this is where the master node points to. The only occasion when the tail of the
log changes is the commit operation.

The commit operation has 2 phases - "commit start" and "commit end". The former
is relatively short, and does not involve much I/O. During this phase we mostly
just build various in-memory lists of the things which have to be written to
the flash media during "commit end" phase.

During the commit start phase, what we do is we "clean" the log. Indeed, the
commit operation will index all the data in the journal, so the entire journal
"disappears", and therefore the data in the log become unneeded. So we just
move the head of the log to the next LEB, and write the CS node there. This LEB
will be the tail of the new log when the commit operation finishes.

When the "commit start" phase finishes, users may write more data to the
file-system, in parallel with the ongoing "commit end" operation. At this point
the log tail was not changed yet, it is the same as it had been before we
started the commit. The log head keeps moving forward, though.

The commit operation now needs to write the new master node, and the new master
node should point to the new log tail. After this the LEBs between the old log
tail and the new log tail can be unmapped and re-used again.

And here is the possible problem. We do 2 operations: (a) We first update the
log tail position in memory (see 'ubifs_log_end_commit()'). (b) And then we
write the master node (see the big lock of code in 'do_commit()').

But nothing prevents the log head from moving forward between (a) and (b), and
the log head may "wrap" now to the old log tail. And when the "wrap" happens,
the contends of the log tail gets erased. Now a power cut happens and we are in
trouble. We end up with the old master node pointing to the old tail, which was
erased. And replay fails because it expects the master node to point to the
correct log tail at all times.

This patch merges the abovementioned (a) and (b) operations by moving the master
node change code to the 'ubifs_log_end_commit()' function, so that it runs with
the log mutex locked, which will prevent the log from being changed benween
operations (a) and (b).

Cc: stable@vger.kernel.org # 07e19dff UBIFS: remove mst_mutex
Cc: stable@vger.kernel.org
Reported-by: Nhujianyang <hujianyang@huawei.com>
Tested-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

We use a circle area to record the log nodes in ubifs. This log area
should not be overlapped. But after researching the code, I found
some conditions may lead log head wraps log ltail. Although we've
fixed the problems discovered, there may be some other issues still
left.

This patch adds assertions where lhead changes to next leb to make
sure ltail is not wrapped.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This reverts commit 545f7fdf.

Hujianyang's testing revealed that the patch is bogus.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Add an assertion which checkes that the head of the log never overlaps with the
tail of the log.
Suggested-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Remove the "if (c->lhead_offs == 0)" check because is unnecessary, since
at that point the log head offset is guaranteed to be zero due to the previous
operation.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The 'mst_mutex' is not needed since because 'ubifs_write_master()' is only
called on the mount path and commit path. The mount path is sequential and
there is no parallelism, and the commit path is also serialized - there is only
one commit going on at a time.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

s/data/timer
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Fix checkpatch warnings:
"WARNING: Prefer seq_puts to seq_printf"

Andrew Morton wrote:

"
- puts is presumably faster

- puts doesn't go rogue if you accidentally pass it a "%".

- this patch actually made fs/ubifs/super.o 12 bytes smaller.
  Perhaps because seq_printf() is a varargs function, forcing the
  caller to pass args on the stack instead of in registers.
"
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

kcalloc manages count*sizeof overflow.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

No grouped argument in drop_last_node.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

In the end of 'create_default_filesystem()' we need to check
the return value of 'ubifs_write_node()' to ensure that we have
successfully written the 'cs_node'.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Randy Dunlap pointed that we should use "scanned" instead of "scaned". This
patch makes the correction.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch fixes some comments about return type.
Signed-off-by: NSeunghun Lee <waydi1@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

We set @ecc in ubifs_scan_leb only if leb_read returns EBADMSG and
do not use it any more. This patch removes this variable and adds
comments about EBADMSG handling.

Artem: re-phrase commentaries
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch removes useless and duplicate statements.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This is a minor fix. These two branches in 'dbg_chk_pnode()'
are dealing with different conditions. Although there is
no fault in current state, I think adding "break"s in
each end of branch is better.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch checks the return value of 'ubifs_unpack_nnode()'.
If this function returns an error, 'nnode' may not be
initialized, so just print an error message and break.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

iter_file_splice_write() - a ->splice_write() instance that gathers the
pipe buffers, builds a bio_vec-based iov_iter covering those and feeds
it to ->write_iter().  A bunch of simple cases coverted to that...

[AV: fixed the braino spotted by Cyrill]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch adds a new ubifs_assert() in ubifs_tnc_close() to check
if there are any leaks of per-filesystem @clean_zn_cnt. This new
assert inspects whether the return value of ubifs_destroy_tnc_subtree()
is equal to @clean_zn_cnt or not while umount.

Artem: a minor amendment
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

When attempting to mount a non-ubifs formatted volume, lots of error
messages (including a stack dump) are thrown to the kernel log even if
the MS_SILENT mount flag is set.
Fix this by introducing adding an additional state-variable in
struct ubifs_info and suppress error messages in ubifs_read_node if
MS_SILENT is set.
Signed-off-by: NDaniel Golle <daniel@makrotopia.org>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I hit the same assert failed as Dolev Raviv reported in Kernel v3.10
shows like this:

[ 9641.164028] UBIFS assert failed in shrink_tnc at 131 (pid 13297)
[ 9641.234078] CPU: 1 PID: 13297 Comm: mmap.test Tainted: G           O 3.10.40 #1
[ 9641.234116] [<c0011a6c>] (unwind_backtrace+0x0/0x12c) from [<c000d0b0>] (show_stack+0x20/0x24)
[ 9641.234137] [<c000d0b0>] (show_stack+0x20/0x24) from [<c0311134>] (dump_stack+0x20/0x28)
[ 9641.234188] [<c0311134>] (dump_stack+0x20/0x28) from [<bf22425c>] (shrink_tnc_trees+0x25c/0x350 [ubifs])
[ 9641.234265] [<bf22425c>] (shrink_tnc_trees+0x25c/0x350 [ubifs]) from [<bf2245ac>] (ubifs_shrinker+0x25c/0x310 [ubifs])
[ 9641.234307] [<bf2245ac>] (ubifs_shrinker+0x25c/0x310 [ubifs]) from [<c00cdad8>] (shrink_slab+0x1d4/0x2f8)
[ 9641.234327] [<c00cdad8>] (shrink_slab+0x1d4/0x2f8) from [<c00d03d0>] (do_try_to_free_pages+0x300/0x544)
[ 9641.234344] [<c00d03d0>] (do_try_to_free_pages+0x300/0x544) from [<c00d0a44>] (try_to_free_pages+0x2d0/0x398)
[ 9641.234363] [<c00d0a44>] (try_to_free_pages+0x2d0/0x398) from [<c00c6a60>] (__alloc_pages_nodemask+0x494/0x7e8)
[ 9641.234382] [<c00c6a60>] (__alloc_pages_nodemask+0x494/0x7e8) from [<c00f62d8>] (new_slab+0x78/0x238)
[ 9641.234400] [<c00f62d8>] (new_slab+0x78/0x238) from [<c031081c>] (__slab_alloc.constprop.42+0x1a4/0x50c)
[ 9641.234419] [<c031081c>] (__slab_alloc.constprop.42+0x1a4/0x50c) from [<c00f80e8>] (kmem_cache_alloc_trace+0x54/0x188)
[ 9641.234459] [<c00f80e8>] (kmem_cache_alloc_trace+0x54/0x188) from [<bf227908>] (do_readpage+0x168/0x468 [ubifs])
[ 9641.234553] [<bf227908>] (do_readpage+0x168/0x468 [ubifs]) from [<bf2296a0>] (ubifs_readpage+0x424/0x464 [ubifs])
[ 9641.234606] [<bf2296a0>] (ubifs_readpage+0x424/0x464 [ubifs]) from [<c00c17c0>] (filemap_fault+0x304/0x418)
[ 9641.234638] [<c00c17c0>] (filemap_fault+0x304/0x418) from [<c00de694>] (__do_fault+0xd4/0x530)
[ 9641.234665] [<c00de694>] (__do_fault+0xd4/0x530) from [<c00e10c0>] (handle_pte_fault+0x480/0xf54)
[ 9641.234690] [<c00e10c0>] (handle_pte_fault+0x480/0xf54) from [<c00e2bf8>] (handle_mm_fault+0x140/0x184)
[ 9641.234716] [<c00e2bf8>] (handle_mm_fault+0x140/0x184) from [<c0316688>] (do_page_fault+0x150/0x3ac)
[ 9641.234737] [<c0316688>] (do_page_fault+0x150/0x3ac) from [<c000842c>] (do_DataAbort+0x3c/0xa0)
[ 9641.234759] [<c000842c>] (do_DataAbort+0x3c/0xa0) from [<c0314e38>] (__dabt_usr+0x38/0x40)

After analyzing the code, I found a condition that may cause this failed
in correct operations. Thus, I think this assertion is wrong and should be
removed.

Suppose there are two clean znodes and one dirty znode in TNC. So the
per-filesystem atomic_t @clean_zn_cnt is (2). If commit start, dirty_znode
is set to COW_ZNODE in get_znodes_to_commit() in case of potentially ops
on this znode. We clear COW bit and DIRTY bit in write_index() without
@tnc_mutex locked. We don't increase @clean_zn_cnt in this place. As the
comments in write_index() shows, if another process hold @tnc_mutex and
dirty this znode after we clean it, @clean_zn_cnt would be decreased to (1).
We will increase @clean_zn_cnt to (2) with @tnc_mutex locked in
free_obsolete_znodes() to keep it right.

If shrink_tnc() performs between decrease and increase, it will release
other 2 clean znodes it holds and found @clean_zn_cnt is less than zero
(1 - 2 = -1), then hit the assertion. Because free_obsolete_znodes() will
soon correct @clean_zn_cnt and no harm to fs in this case, I think this
assertion could be removed.

2 clean zondes and 1 dirty znode, @clean_zn_cnt == 2

Thread A (commit)         Thread B (write or others)       Thread C (shrinker)
->write_index
   ->clear_bit(DIRTY_NODE)
   ->clear_bit(COW_ZNODE)

            @clean_zn_cnt == 2
                          ->mutex_locked(&tnc_mutex)
                          ->dirty_cow_znode
                              ->!ubifs_zn_cow(znode)
                              ->!test_and_set_bit(DIRTY_NODE)
                              ->atomic_dec(&clean_zn_cnt)
                          ->mutex_unlocked(&tnc_mutex)

            @clean_zn_cnt == 1
                                                           ->mutex_locked(&tnc_mutex)
                                                           ->shrink_tnc
                                                             ->destroy_tnc_subtree
                                                             ->atomic_sub(&clean_zn_cnt, 2)
                                                             ->ubifs_assert  <- hit
                                                           ->mutex_unlocked(&tnc_mutex)

            @clean_zn_cnt == -1
->mutex_lock(&tnc_mutex)
->free_obsolete_znodes
   ->atomic_inc(&clean_zn_cnt)
->mutux_unlock(&tnc_mutex)

            @clean_zn_cnt == 0 (correct after shrink)
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The debugging check which verifies that we never write outside of the file
length was incorrect, since it was multiplying file length by the page size,
instead of dividing. Fix this.
Spotted-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

If UBIFS_DEBUG is defined an additional assertion of the ui_lock
spinlock in do_writepage cannot compile because the ui pointer has not
been previously declared.

Fix this by declaring and initializing the ui pointer in case
UBIFS_DEBUG is defined.
Signed-off-by: NDaniel Golle <daniel@makrotopia.org>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Function ubifs_read_one_lp will not set @lp and returns
an error when ubifs_read_one_lp failed. We should not
perform ubifs_dump_lprop in this case because @lp is not
initialized as we wanted.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I found two variables in ubifs_budget_space declared but not
use. This state remains since the first commit 1e5176. So just
remove them.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

There is a race condition in UBIFS:

Thread A (mmap)                        Thread B (fsync)

->__do_fault                           ->write_cache_pages
   -> ubifs_vm_page_mkwrite
       -> budget_space
       -> lock_page
       -> release/convert_page_budget
       -> SetPagePrivate
       -> TestSetPageDirty
       -> unlock_page
                                       -> lock_page
                                           -> TestClearPageDirty
                                           -> ubifs_writepage
                                               -> do_writepage
                                                   -> release_budget
                                                   -> ClearPagePrivate
                                                   -> unlock_page
   -> !(ret & VM_FAULT_LOCKED)
   -> lock_page
   -> set_page_dirty
       -> ubifs_set_page_dirty
           -> TestSetPageDirty (set page dirty without budgeting)
   -> unlock_page

This leads to situation where we have a diry page but no budget allocated for
this page, so further write-back may fail with -ENOSPC.

In this fix we return from page_mkwrite without performing unlock_page. We
return VM_FAULT_LOCKED instead. After doing this, the race above will not
happen.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Tested-by: NLaurence Withers <lwithers@guralp.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Dan's "smatch" checker found out that there was a bug in the error path of the
'ubifs_remount_rw()' function. Instead of jumping to the "out" label which
cleans-things up, we just returned.

This patch fixes the problem.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Mostly scripted conversion of the smp_mb__* barriers.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

filemap_map_pages() is generic implementation of ->map_pages() for
filesystems who uses page cache.

It should be safe to use filemap_map_pages() for ->map_pages() if
filesystem use filemap_fault() for ->fault().
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ning Qu <quning@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Reviewed-by: NMinchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>